Healthcare reform has resulted in sicker patients being cared for in the home and extended care facilities. Patients who require long term mechanical ventilation represent a special needs group within this population. The single greatest impediment to quality of life in the ventilator-assisted individual is portability. Current generation ventilators in general, are large, heavy (approximately 30 Ibs.), and require significant battery power. The investigators have previously developed a robust, high performance ventilator weighing only 12 Ibs. This product captured >20% of the home care ventilator market in < 2 years, validating the importance of portability. This application proposes developing the next generation truly portable "Palm Top Ventilation'. Three small, lighter-weight (6 Ibs.), ventilator prototypes, which produce air via an energy efficient roots blower, will be designed and built. The investigative plan includes: 1) building on the knowledge gained during the Phase I activities, complete the development of the Roots blower into a commercially manufacturability component. Cost effectiveness, manufacturing repeatability, and long term reliability of the blower will be evaluated; 2) reducing the noise output of the roots blower based P'IV to under 45 dbA as measured at one meter from the ventilator; 3) developing the software based control algorithms enabling the ventilator to deliver the entire range of ventilation modes and breath types including Volume Controlled (VC)breaths, Pressure Controlled (PC) breaths, and hybrid VC/PC breaths; 4) developing a robust product package that will enable the device to survive the extreme shock and vibration associated with transport, including 100 g shocks and being dropped from a height of 36"; and 5) completing the initial bench testing and human subject testing.